如何在android中禁用主页和最近的应用程序按钮

Question

如何禁用android中的所有物理可见按钮我尝试了followind代码 在此代码后退按钮被禁用但主页按钮仍然有效.. 请帮助我，我被困在我的项目中

import android.app.Activity;
import android.app.KeyguardManager;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.WindowManager;
public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    findViewById(R.id.hello_text).setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            System.exit(0);
        }
    });


}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    // TODO Auto-generated method stub
    if(event.getKeyCode()==KeyEvent.KEYCODE_BACK){
        return false;
    }
    if(event.getKeyCode()==KeyEvent.KEYCODE_HOME){
        return false;
    }
    return super.onKeyDown(keyCode, event);
}
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
    // TODO Auto-generated method stub
    if(event.getKeyCode()==KeyEvent.KEYCODE_BACK){
        return false;
    }
    if(event.getKeyCode()==KeyEvent.KEYCODE_HOME){
        return false;
    }
    return super.onKeyUp(keyCode, event);
}

}

清单文件

 <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sampledisplayonapp"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="11"
    android:targetSdkVersion="22" />

     <uses-permission android:name="android.permission.DISABLE_KEYGUARD"></uses-permission>  


<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.Holo.NoActionBar.Fullscreen" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>

            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>